Adding Vectors

I tried diong (6cos60, 6 sin 60) + (4cos160, 4 sin160) + (3cos330, 3sin330)
and i got what the answer should be
(5.06, 1.84), except theothe rway round (1.84, 5.06) i thogutht he cos gets the X, why did i have the switch. or is my approach all wrong. causei used the angles id get if i started from t he top of the y-axis.